The present invention relates generally to in-ground locating using a portable locator and, more particularly, to a able locator including an integral ground marking arrangement.
Portable locators have become popular, for example, as part of locating arrangements used with underground horizontal boring equipment. In particular, hand held portable locators enable tracking of a boring tool which is configured for emitting a locating field from the position of the boring tool beneath the surface of the ground. As examples of state of the art locating systems which incorporate portable walk over locators see U.S. Patent No. 4,387,380 entitled APPARATUS FOR DETERMINING THE DISTANCE TO A CONCEALED OBJECT WHICH IS RADIATING AN ALTERNATING CURRENT SIGNAL (hereinafter the ""380 patent) and U.S. Patent No. 5,633,589 entitled DEVICE AND METHOD FOR LOCATING AN INGROUND OBJECT AND A HOUSING FORMING PART OF SAID DEVICE (hereinafter the ""589 patent). It is noted that the latter patent is commonly assigned with the present application.
The ""589 patent utilizes a hand held portable locator which can be held at a user determined height above the surface of the ground. Because the height of the locator above the surface of the ground has a critical effect on locating measurements, an ultrasonic detecting arrangement within the locator senses the distance between the surface and the portable locator during measurements of the locating field.
The portable locator of the ""340 patent, in contrast, utilizes a stand-off leg for establishing locator height. When locating field measurements are taken, the lower end of the stand-off leg is positioned on the surface of the ground so as to fix the height of the measurement point within the locator at a predetermined distance above the surface of the ground.
In the normal course of a horizontal drilling operation, using either of the aforedescribed portable locator styles, it is often desired to mark the surface of the ground directly above the underground path of the boring tool or to make other reference marks. To that end, the operator of the portable locator will often carry some sort of marking device such as a canister of aerosol paint. Aerosol paint canisters are readily available in various configurations for marking the surface of the ground. Moreover, extension handles are also available and are popular for holding one of these aerosol canisters, the combination of which may be referred to hereinafter as a marking wand. Using a marking wand, the operator can mark the surface of the ground from a substantially upright position. An operator can determine a location on the surface of the ground using the locator in one hand and then swing the portable locator out of the way to mark the surface of the ground with paint by having the marking wand in the other hand. While this arrangement seems generally convenient, it is unfortunate that still further tasks are normally required of the locator operator, as will be described immediately hereinafter.
In addition to operating the portable locator while marking the surface of the ground, the locator operator is normally required to communicate guidance commands to another operator stationed at a drill rig powering the underground boring tool. This communication, in most instances, is performed using walkie-talkies. With the portable locator in one hand and the marking wand in the other, the portable locator operator must typically place either the marking wand or the locator on the ground in order to free one hand for operating the walkie-talkie. In this regard, it should be appreciated that the aerosol marking wand and portable locator are each somewhat bulky and inconvenient to repeatedly place on the ground and pick up. Moreover, there may be situations in which the portable locator itself requires two hands to operate or the operator requires a free hand for additional tasks such as, for example, recording log entries or using a walkie-talkie to issue drilling commands. For these and other reasons, portable locator operators are seen to encounter problems in having an insufficient number of hands to operate three or more separate devices, all of which are important to the drilling operation.
The present invention provides a portable locator having an integral ground marking arrangement which serves to reduce or eliminate the foregoing problems in a highly advantageous and heretofore unseen way.
As will be described in more detail hereinafter, there is disclosed herein an improvement in a portable locator configured for locating relative to a position beneath the surface of the ground. The improvement being a marking arrangement for marking the surface of the ground.
In one aspect of the invention the portable locator is configured having a marking arrangement which utilizes a replaceable aerosol paint canister. Spray of paint from the canister may be initiated, for example, electrically or using a suitable mechanical actuation linkage.
In another aspect of the invention, an operator of the portable locator of the present invention is able to mark the surface of the ground using the portable locator and while holding the portable locator in generally the same position and/or stance as the locator is used for locating purposes.